Hi All
I have modelled a shell surface for a modal acoustic analysis. but run exits with this error , how should I resolve it ?
All nodes of the elements attaching to PML interface with the PML
element coordinate system number 0 have zero pressure constraint for
the acoustic element FLUID30, FLUID220 or FLUID221. Please check the
constraint applied on the PML elements. This error may also be caused
by the connectivity of FEA model. Using the NUMMRG command may avoid
the error.